Volume 2, Issue 16 |
July 25, 2008 | |

Upcoming Events
Aug. 17-21: 138th AFS Annual Meeting
Sep. 11: TRTAC
Sep. 26-28: Salmonid Restoration Federation 11th Annual Coho Confab
Oct. 22-24: CALFED Science Conference
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Key Highlights
2007/08 Juvenile Migration Monitoring. Rotary Screw Trap sampling for the 2007/2008 season ended at the last three remaining stations during this reporting period: Shelton Road on the Calaveras River and at Oakdale and Caswell sites on the Stanislaus River. The last trawling day at Mossdale (San Joaquin River) was conducted on June 30.
San Joaquin River Conditions. San Joaquin River water temperatures and dissolved oxygen (DO) fluctuated throughout the reporting period at both Mossdale and the deepwater ship channel with an overall increasing trend for water temperatures observed.
Delta Exports. Combined total exports (state and federal pumps) exhibited an overall increase, ranging between 1,732 cfs (June 23) and 6,314 cfs (July 8).
We encourage subscribers to contribute any relevant information for future issues of the newsletter (e.g., additional monitoring studies, announcements of upcoming meetings and events, etc). If you would like to contribute, please contact Chrissy Sonke.
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2007/08 Migration Monitoring
The Calaveras River rotary screw trap at Shelton Road (RM 29) sampled 11 out of 19 days between June 23 and July 11. The Calaveras juvenile migration monitoring season was ended on July 11, 2008.
A total of 100 O. mykiss were captured during the reporting period, increasing the season total to 1,871. Daily catch ranged between three and 27 O. mykiss. A total of 89 young-of-year (YOY; ≤100 mm) and 11 Age 1+ (101-299 mm) O. mykiss were captured. Average forklengths and weights of O. mykiss are provided in Table 1. Most of the O. mykiss captured and measured were rated as parr (n=73); however, there were also some silvery parr (n=26), smolts (n=2), and one fry.
No Chinook were captured during this reporting period.


Table 1. Biosampling data for O. mykiss captured and measured at Shelton Road between June 23 and July 11, 2008. Parentheses indicate range.
Instantaneous temperatures taken at the trap ranged from 55�F to 58�F, and turbidity ranged from 0.1 NTU to 1.0 NTU. Daily average flow fluctuated between 186 cfs and 268 cfs at New Hogan Dam (NHG), between 34 cfs and 65 cfs at Bellota (MRS), and zero cfs at Cosgrove (COS).

The Stanislaus River rotary screw trap at Oakdale (RM 40) sampled six out of 10 days between June 23 and July 2. The Stanislaus juvenile migration monitoring season at Oakdale Recreation Area was ended on July 2, 2008.
A total of 11 juvenile Chinook salmon were captured during the reporting period, increasing the season total to 21,886. Daily catch ranged between zero and five Chinook. Average forklengths and weights of Chinook salmon are provided in Table 2. All measured Chinook were smolts (n=11).
Two Age 1+ (i.e., 100-299 mm) O. mykiss were captured during this reporting period (Table 2). One of the captured O. mykiss was exhibiting smolt characteristics.


Table 2. Biosampling data for Chinook salmon and O. mykiss captured and measured at Oakdale between June 23 and July 2, 2008. Parentheses indicate range. Note: only one O. mykiss was weighed.

Instantaneous temperature taken at the trap ranged from 59�F to 60�F, and turbidity ranged from 0.2 NTU to 2.1 NTU. Daily average flow fluctuated between 449 cfs and 506 cfs at Goodwin Dam (GDW) and fluctuated between 457 cfs and 497 cfs at Orange Blossom Bridge (OBB). No trap efficiency releases were conducted during this reporting period. The Stanislaus River rotary screw trap at Caswell (RM 8) monitoring season ended on June 25. The season total catch at Caswell was 229 Chinook. Average forklengths and weights of Chinook salmon that were measured during the season are provided in Table 3. The smolt lifestage dominated the juvenile outmigration, comprising 86.9% of the season total catch, the fry lifestage comprised 12.7%, and the parr lifestage comprised 0.44%. One O. mykiss smolt was captured during the monitoring season.
Table 3. Biosampling data for Chinook salmon captured and measured at Caswell; January 16 to June 25, 2008. Parentheses indicate range. Lifestage was determined using the smolt index table described by CDFG.


The Merced River rotary screw traps at Hatfield (RM 2) monitoring season ended during the last reporting period however final catch numbers are now available. The season total catch at Hatfield was 60 Chinook. Average forklengths and weights of Chinook salmon are provided in Table 4. The smolt lifestage dominated the juvenile outmigration, comprising 98.3% of the season total catch, and the fry lifestage comprised 1.7%. No O. mykiss were captured during the monitoring season. Table 4. Biosampling data for Chinook salmon captured and measured at Hatfield; March 3 to June 5, 2008. Parentheses indicate range. Lifestage was determined using the smolt index table described by CDFG.
  The San Joaquin River trawl sampling at Mossdale (RM 54) was conducted four out of eight days between June 23 and June 30 by the California Department of Fish and Game. The last trawling day for the season was June 30. One Chinook was captured on June 27.
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San Joaquin River Conditions
During the reporting period, flows in the San Joaquin River at Vernalis fluctuated between 877 cfs and 1,035 cfs (avg: 954 cfs). Water temperatures in the San Joaquin exhibited an overall increasing trend with fluctuations between 71.6 �F and 81.1 �F (avg: 76.2 �F) at Vernalis; between 74.4 �F and 82.9 �F (avg: 77.7 �F) at Mossdale; and between 76.8 �F and 80.5 �F (avg: 78.1 �F) at Rough 'n Ready Island. Dissolved oxygen (DO) in the San Joaquin River fluctuated between 5.4 mg/L and 7.4 mg/L (avg: 6.4 mg/L) in the deep water ship channel (measured at Rough 'n Ready Island) and between 9.0 mg/L and 12.7 mg/L (avg: 11.3 mg/L) at Mossdale.
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Delta Exports
 Mean daily pumping at the C.W. Jones Pumping Plant (federal pumps previously known as Tracy Pumping Plant) increased from 1,013 cfs (June 26) to 3,726 cfs (July 11). Mean daily pumping at the Harvey O. Banks Pumping Plant (state pumps) ranged between 714 cfs and 3,093 cfs. Combined total exports (state and federal pumps) exhibited an overall increase, ranging between 1,732 cfs (June 23) and 6,314 cfs (July 8).
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